Manufacture of three dimensional (3D) models or objects is an additive manufacturing process by means of which a computer generated 3D model is converted into a physical object. The process, sometimes termed stereo-lithography, involves generation of a plurality of material layers of different or identical shapes that are laid down or deposited on top (or bottom) of each of the preceding layer until the amount of layers results in a desired physical object.
The material from which the layers of the physical object are generated could come in liquid, paste, powder, gel and other aggregate state. The materials are dispensed by a plurality of methods including inkjet printing, extrusion and sintering. Conversion of such materials into a solid form is typically performed by suitable actinic radiation and/or heat.
Manufacturing of 3D models and objects spans over a large range of applications. This includes prototype manufacture, small runs of different products manufacture, decorations, sculptures, architectural models, and other physical objects.
Recently, manufacture of relatively large size physical objects and models has become popular. Large size statues, animal figures, signage letter, and decorations are manufactured and used in different carnivals, playgrounds, and supermarkets. Where the manufacturing technology allows, some of these physical objects are manufactured as a single piece at 1:1 scale and some are coming in parts assembled into the physical object at the installation site. Manufacturing of such large objects consumes significant amount of relatively expensive materials and techniques to reduce the amount of the expensive materials by including in the manufactured object different support or reinforcement structures have been developed. Methods for manufacture of such supports or reinforcement structures are described for example, in U.S. Pat. Nos. 5,595,703; 6,797,351; 8,285,411; and US Patent Application Publication 2010/0042241.
Introduction of support or reinforcement structures allows small savings on material costs since some of the objects are manufactured as shells or hollow structures. However, large shells could warp, or otherwise deform even in course of their manufacture and multiple support structures integral with the shells or constructed at the installation sites are required. Since the objects manufactured as shells have their inner space hollow or empty, the support structures are mounted or manufactured to be located in these hollow spaces. Although for some shells, the support structures located in the hollow inner space are not sufficient and frequently they become augmented with outer support structure that in addition to cost adversely affect the visual appearance of the object. These support structures significantly increase the object production time, consume costly material, and require additional labor to install them and to remove some of the unnecessary material.